General and Abdominal Obesity and Risk of Death Among Black Women

Study Questions:

What is the relation of general and abdominal obesity to the risk of death in black women?

Methods:

The investigators prospectively assessed the relation of both body mass index (BMI) and waist circumference to the risk of death among 51,695 black women with no history of cancer or cardiovascular disease who were 21-69 years of age at study enrollment. Their analysis was based on follow-up data from 1995 through 2008 in the Black Women’s Health Study. Multivariable proportional-hazards models were used to estimate hazard ratios and 95% confidence intervals.

Results:

Of 1,773 deaths identified during follow-up, 770 occurred among 33,916 women who had never smoked. Among nonsmokers, the risk of death was lowest for a BMI of 20.0-24.9. For a BMI above this range, the risk of death increased as the BMI increased. With a BMI of 22.5-24.9 as the reference category, multivariable-adjusted hazard ratios were 1.12 (95% confidence interval [CI], 0.87-1.44) for a BMI of 25.0-27.4, 1.31 (95% CI, 1.01-1.72) for a BMI of 27.5-29.9, 1.27 (95% CI, 0.99-1.64) for a BMI of 30.0-34.9, 1.51 (95% CI, 1.13-2.02) for a BMI of 35.0-39.9, and 2.19 (95% CI, 1.62-2.95) for a BMI of 40.0-49.9 (p < 0.001 for trend). A large waist circumference was associated with an increased risk of death from any cause among women with a BMI of <30.0.

Conclusions:

The authors concluded that the risk of death from any cause among black women increased with an increasing BMI of 25.0 or higher.

Perspective:

This large prospective study suggests that the risk of death from any cause among black women was lowest among women with a BMI of 20.0-24.9, with an increased risk of death for all categories of BMI in the overweight and obesity range. A larger waist circumference was associated with an increase in the risk of death from any cause only among nonobese nonsmokers. Future studies will need to assess the survival advantage conferred on those individuals who lose weight.